[DGD] Re: DGD vs. MudOS

[George Reese]

Kevin Carpenter wrote:
> 
> Andrew -
> 
> I've been running a DGD based conversation mud for a couple of years now.
> I can tell you why I selected it over MudOS:
> 
> 1) It runs continuously.  I've had my mud up, without needs for reboots,
> for over 60 days at one point.

I have had muds up under MudOS for over 8 weeks as well :)
 
> 2) If I had a reason to, I could code it so that the game environment
> survived system and driver restarts making it appear like it never
> went down.

Nightmare, a MudOS mud, *is* coded that way with small exceptions. 
Namely, we do not retain the state of rooms themselves.  If we found
that to be important, we could do that as well.

Bottom line: both drivers allow you to shutdown and restart as if
nothing had happened. 

> 3) I have hosted MudOS based muds that have to be rebooted once or
> twice a day to relieve memory leakage problems.  One of the MudOS muds
> I hosted would grow from around 2.5mb to 24mb in about 16 hours.  I
> can basically tune my mud to use whatever storage I care to, having it
> swap to disk as needed.  FWIW - I have my mud monitor its memory usage
> and swapout() whenever it exceeds 6mb.

This is an issue of disk based versus memory based.  I prefer RAM based.
Either way, the muds take up as much storage.  It is a question of where
they are stored.  RAM is more expensive, disk access is slower.  On a
mud machine, however, I believe the RAM downside to be negligible and
the diska access cost to be more problematic.  People constrained by
RAM, however, are certain to feel different.
 
> 4) MudOS is a collective project (or at least it was) written by many
> people over many years.  As such, there is often several ways, often
> with several side-effects, to do even simple things like writing a
> message to a user.  Having Felix be the sole driver maintainer results
> in a clean driver.

Messaging is an extreme example.  While DGD is a cleaner driver in terms
of code, that only really effects people who want to modify the driver. 

> 5) With 20-40 people logged in, admitted only conversing, not do any
> CPU intensive things like combat, my mud consumes about 3% of my 120Mhz
> 486.  I don't really care if MudOS is marginally faster processing some
> implementation detail.

I agree here.  The relative processing speed of both drivers is
irrelevant.  They are both fast enough.  Pick the one that suits your
other needs.

> Don't be concerned with DGD being "disk based".  That adds flexibility,
> and would only become a performance concern under weird conditions
> (like you having a 10mb mapping that you routinely scan, but only
> have 5mb of memory for the mud).  My log file IO rate is probably
> an order of magnitude higher than my swap file usage.  The only
> problem I've had is that it can take some time to write out a dump
> file, if you want to restart later.  I've had some problems with
> getting a test version of the mud to do this within the normal UNIX
> shutdown period.

Log file I/O can be reduced by going MT with log I/O.  Beyond that, I do
think being disk-based is a disadvantage if you have the RAM.  It is a
bonus if you do not.

-- 
George Reese (borg at imaginary.com)       http://www.imaginary.com/~borg
     "In our fear, we make an image, and that image we call God."
		  Antonius Block in The Seventh Seal
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